The present invention provides a gauge for measuring a horizontal dimension and more particularly, a gauge useful in measuring the wheelbase of a cast steel railway freight car sideframe.
The traditional three-piece railway freight car truck is comprised of two cast steel sideframes that are identical in design and are aligned parallel with the railway track. A bolster opening is located at a central portion of each sideframe to receive a spring group upon which a cast steel bolster is supported. Thusly, a three piece railway freight car truck is comprised of three major structural components, the two sideframes and the transversely mounted bolster. Each sideframe also includes pedestal jaws near each end thereof for receipt of a roller bearing assembly and, in turn, the end of a railway freight car axle. The wheels of such axle are mounted laterally inboard from the sideframe.
It is desirable in assembling the three-piece railway freight car truck to have the axles as parallel as possible to assist in steering and to improve other performance characteristics of the railway freight car truck. Accordingly, it is desirable to utilize two sideframes that have as nearly as possible the same wheelbase such that the axles when received in the pedestal jaws of the opposite sideframes are nearly as parallel as possible. Wheelbase is of course the horizontal spacing between the pedestal jaws of each sideframe.
A prior art wheelbase gauge is known and in use in certain foundries that produce cast steel sideframes. Such wheelbase gauge is comprised of two elongated aluminum rectangular bar stock sections joined by two sliding fit support braces. Each support brace is located about one quarter the length of the entire wheelbase gauge inward from each end of the wheelbase gauge. In use, such wheelbase gauge is usually placed on a railway freight car sideframe that is lying on its side on an appropriate holding table. Such prior art wheelbase gauge includes depending legs that are affixed near either end of the gauge and extend downwardly therefrom. In placing such prior art gauge on a cast steel sideframe, each depending leg is placed into one of the pedestal jaws of the sideframe and the two main sections of the gauge are moved relative to each other such that a horizontally outboard edge of one leg and a horizontally inboard edge of another leg contact respective edges of the pedestal jaw. The gauge is then moved horizontally such that the other edges of the depending legs contact the other edges of the pedestal jaw. Readings are made from each of the two contact positions and averaged to come up with the wheelbase for the sideframe.
It is known that errors can occur due to the difficulty in the relative sliding of each component main section of the wheelbase gauge for there is the possibility of bending under horizontal force applied by the two workers who must position the gauge on the sideframe. One worker must pull the respective end of the gauge and the other worker must push the respective end of the gauge in order to contact the edges of the sideframe pedestal jaws. The process is then repeated in reverse wherein the first worker is pushing his end of the gauge into contact with an inboard end of the pedestal jaw whereas the other worker is pulling his end of the gauge into contact with an outboard edge of the pedestal jaw. Adding to the difficulty was the weight of this wheelbase gauge, about 85 lbs.
A first measurement reading was taken by comparing indicator lines etched in the top of one section of the main gauge body with a reference line on the top of the other section of the main gauge body for a standard size of sideframe thereby determining if the wheelbase was exact or slightly oversized or slightly undersized. An indication was then provided on each sideframe by leaving an appropriate number of protruding dots to indicate whether the sideframe was slightly oversized or undersized from the standard wheelbase. Similarly sized sideframes would be assembled in the same freight car truck. Further details and description of the prior art wheelbase gauge will be provided in the detailed description.